KR20010042710A - Turbocharged internal combustion engine - Google Patents

Abstract

The present invention relates to a turbocharged internal combustion engine (10), which comprises at least one high pressure stage (20) and at least one low pressure stage (30) disposed downstream of the high pressure stage (20), Bypass pipes 24a and 24b having pipe switches 70 and 71 connecting the exhaust piece 12 of the engine 10 to the inlet piece of the low pressure turbine 31 and the operating parameters of the engine 10 are sensed. It is configured to include a sensor for. The high pressure turbine 21 always operates at the lowest displacement, which continuously circulates, and is equipped with a central processing unit (CPU) to receive signals from the sensor, and the CPU allows the pipe switches 70 and 71 to change the total displacement. The operating mode of the engine 10 so that the possible parts are distributed and flow into the new air pieces of the high pressure turbine 21 and the low pressure turbine 31 and the engine 10 to minimize fuel consumption and / or displacement. Try to optimize all of them.

Description

Turbocharged internal combustion engine

Such an internal combustion engine having a two-step supercharging process is disclosed in DE 195 14 572 A1, in which the high and low pressure stages are linked to a turbocharger in the low speed range of the internal combustion engine. The initial exhaust flows to the high pressure turbine and then to the low pressure turbine. The turbocharged air is first compressed by a low pressure compressor and then by a high pressure compressor, cooled in a heat exchanger and then injected into the new air of the internal combustion engine. As the circulation speed of the internal combustion engine increases, it is converted into a single stage compression process, which is compressed only in low pressure compressors, so that the high pressure turbine is completely bypassed by the exhaust pipe switch, and the high pressure compressor is connected to the turbocharged air pipe switch. Can be bypassed completely.

However, the conversion in such turbocharging process often raises the load and produces a change in the speed of the internal combustion engine, and often such a change has to occur between one and two stages of turbocharging device operation. Thus, a loss of riding comfort and non-continuous acceleration and braking power reactions occur.

An internal combustion engine according to the introduction to the claims is also disclosed in DE 39 03 563 C1. However, in the above patent, the turbocharging takes place from two stages to one stage, which is caused by a pipe switch installed between the outlet piece and the high-pressure turbine, and thus also a loss of ride comfort.

The present invention relates to a turbocharged internal combustion engine as described in the introduction of claim 1, and more particularly to a turbocharged internal combustion engine having at least one pressure reduction stage at high and low pressures. The turbine may be formed in a single flow or double flow type, and the inlet side of the high pressure turbine may be connected to the exhaust side of the engine, and the outlet side may be connected to the low pressure turbine. It may include at least one bypass channel (Bypass Channel) lockable by a pipe switch connecting the exhaust piece to the low pressure turbine.

1A is a circulation diagram showing the exhaust and fresh air flow of a turbocharged diesel internal combustion engine in two stages with a paired bypass flow;

1B is a circulation diagram showing the exhaust flow of a diesel internal combustion engine turbocharged in two stages with a common bypass flow;

2 is a circulation diagram showing the exhaust flow of a turbocharged diesel internal combustion engine in two stages with a paired bypass flow for a dual flow low pressure turbine;

3 is a circulation diagram showing the flow of exhaust and fresh air according to FIG. 1A with a low pressure bypass;

4 is a circulation diagram showing the exhaust and fresh air flow of a V-type diesel internal combustion engine turbocharged in two stages;

5 and 6 are different circulation diagrams in which various arrangements of turbines are used as high pressure turbines,

7 is a circular diagram illustrating a particular bypass arrangement.

<Explanation of symbols for main parts of drawing>

10: diesel internal combustion engine 11: new air

12: exhaust piece 13a, b: cylinder row

20: high pressure stage 21: high pressure turbine

22: high pressure compressor 23a, b: flow

24, 24a, b: bypass channel 30: low pressure stage

31 low pressure turbine 32 low pressure compressor

33a, b: flow 34: bypass section

40: turbocharged air cooler 50: exhaust return

60, 61, 62, 62a, b: pipe 63, 63a, b: mouse point

70, 71, 72: pipe switch 80: motor controller

86: bypass line 87: pipe switch

The present invention is to solve the problems of the internal combustion engine according to the introduction of claim 1 to respond to rapid load, and for a shift that does not cause a continuous braking power response. Turbocharge pressure is an acceleration, that is, it does not delay when the vehicle is accelerated, so that it can be applied infinitely and variously to the engine demand.

This object of the invention can be solved by the features of the independent claims.

In particular, according to a feature of the invention there is a continuous flow through the high-pressure turbine at least to some extent, and because the flow rotates, the lowest turbocharge pressure occurs when accelerating, in particular the rotational speed of the HP rotor is at the most desirable initial level. Will be. In addition, each exhaust flow can be supplied to the high pressure turbine, the low pressure turbine or the new air piece to the extent required in each case according to the configuration of the present invention having a central processing unit and a pipe switch, so that the engine operating mode is the lowest fuel. It can be optimized to have a consumption and the lowest displacement.

The high pressure turbine reacts quickly so that it can respond appropriately to the load and increase the engine's rotational speed because the expansion operation moves in the direction of the high pressure turbine. That is, the bypass channel is almost closed by the pipe switch so that most of the exhaust flow is injected into the high pressure turbine. If low fuel consumption, low load and, above all, exhaust response pressure are required in this operating range when the load is low and the displacement is small, the expansion operation of the exhaust is performed by properly positioning the pipe switch after exhaust return and by rotating the engine by opening the bypass channel. Independent speeds can cause most of the low pressure turbines.

The pipe switch is connected to a motor electronic system that records the operating characteristics of the engine, such as rotation speed, displacement, turbocharge pressure, turbocharge air temperature, and can be controlled in an operating mode that minimizes fuel consumption and displacement depending on the engine's operating conditions. have. As a result, the lowest fuel consumption and lowest displacement are adjusted for optimum conditions. Depending on the atmospheric conditions, the separation of load conditions, rotational speeds and optimized exhaust flows will be formed in new air planes, high pressure turbines and low pressure turbines.

Another advantage of enabling the distribution of displacement is that the operating line runs according to the operating characteristics of the high and low pressure compressors, on the one hand, which improves the compressor's efficiency, while on the other hand the pumping remains substantially below extreme. Done.

Unlike the first main technique of the present invention already described, according to the second main technique of the present invention, the following effects can also be obtained.

The bypass channel connecting the internal combustion engine to the inlet side of the low pressure turbine is not absolutely necessary. One of the two turbines, preferably the high pressure turbine, can have a variable arrangement and, above all, can be provided with distribution means having suitable vanes. For example, if such a distribution means is provided in the high pressure turbine, even if the entire flow is through the high pressure turbine, the ratio of the flow can be adjusted to be larger or smaller.

In addition, a bypass pipe with a pipe switch can be provided, through which the high pressure turbine can be bypassed. The distribution means are also always slightly open so that at least the minimum displacement flows reliably through the high pressure turbine, so there is always at least the lowest turbocharge pressure, in particular the rotational speed of the HP rotor is at the desired initial level. Additional control may be provided by the pipe switch.

In any case, the advantage of using one of the two major technologies described above is that the operating parameters of the internal combustion engine can be very sensitively varied.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

The six-cylinder diesel internal combustion engine 10 shown in FIG. 1 is turbocharged in two stages by a turbocharger. To this end, the high pressure stage 20 is arranged before a single low pressure stage 30. The new air is compressed by the compressors 22 and 32 driven by the high pressure turbine 21 and the low pressure turbine 31, cooled in two turbocharged air coolers 40, and exhausted from the exhaust return flow 50. And a certain percentage (_0) is mixed into the new air piece 11 of the engine (10). The rotor diameter of the low pressure turbine 32 is larger than the rotor diameter of the high pressure turbine 21, and the rotor diameter ratio d _{L, ND} / d _{L, HD} between the low pressure and the high pressure turbine is about 1.2 to 1.8. The two flows 23a and b of the dual flow of the high pressure turbine 21 are connected to the exhaust piece 12 of the engine by pipes 60 and 61 at the inlet side, respectively. At the outlet piece, the flows 23a and b are connected to the common pipe 62 which in turn is connected to the inlet piece of the low pressure turbine 31 of a single flow via the outlet piece pipes 63 and 64. One of the two turbocharged air coolers can of course be omitted.

In the optimum application state of the turbocharger according to the operating state of the engine 10, the bypass channels 24a, 24b are arranged symmetrically with respect to the respective flows 23a, b of the high pressure turbine 21. Each flows into separate pipes 60, 61 of the exhaust elbow and bypasses the high pressure turbine 20 to a common pipe 62 for a single supply to the low pressure turbine 30 in a single flow. Each bypass channel 24a, b is provided with pipe switches 70,71 arranged in the downstream direction of the flow. Such a structure may be installed in the housing of an exhaust elbow or a high pressure turbine, may have the shape of a similar device such as a slide, a valve, a flap, or the like, or may be controlled by a CPU singly or in common.

In addition, the exhaust return pipe 50 is connected to the compressor 22 relative to the new air piece 11 back. The amount returned in the exhaust can also be injected into any other point of the fresh air piece. The pipe switch 70 on the one hand allows the bypass channel 24a to be closed and on the other hand the bypass channel 24a to be opened so that a partial flow is applied to the low pressure turbine 30 and the exhaust return pipe 50. It can distribute in the required ratio (exhaust gas recycle ratio≥0). In addition, the pipe switches 70, 71, 50 are connected to the electronic motor controller 80 for the control of the pipe switches 70, 71, 50 functioning as the operating characteristic variables a1-n. Enables optimal distribution of displacement for operation. The bypass ratios 24a and b can be adjusted differently so that the total displacement distribution can be more free.

1b shows another embodiment of the internal combustion engine 10. This is different from that of the turbocharger in FIG. 1A. That is, the outlet side connection of the high pressure turbine 21 is provided downstream of the common pipe 62 of the mouse point 63 of the two bypass channels 24a and b, which is different from that provided upstream in FIG.

2 shows a third embodiment of an internal combustion engine 10. Here, the low pressure turbine 30 is formed in double flow. The two channels 33a, b of the low pressure turbine 31 are provided from different pipes 62a, 62b, respectively, so that the low pressure turbine can be provided with an uneven flow. Bypass channels 24a and b are also flowed separately into different flows 33a and 33b, which flows 23a and b of high-pressure turbine 21 into separate pipes 62a and 62b, respectively. Same as

The internal combustion engine shown in FIG. 3 has a low pressure turbine 31 having a bypass portion 34, which bypasses the pipe switch 72 for optimization of precompression functioning with operating characteristics a1-n. Can be controlled. This is particularly suitable for applications (passenger cars), for example, to avoid the need for cooling of the compressor air between the high pressure compressor 22 and the low pressure compressor 32 due to space problems. Through this, the precompression can be limited to the intended range in the region of the estimated power of the engine 10 by the low pressure step 30.

Very low pressure 31 can be used through the bypass pipe 34 with the pipe switch 72. This increases the braking power during overrun of the engine. The acceleration response of the engine can thus be improved with this. In addition, the corresponding pressures of the turbocharge and exhaust can be further reduced in some operating ranges, which can further increase the efficiency of the internal combustion engine.

4 shows the V8 type as the fifth embodiment of the internal combustion engine 10. Each cylinder row 13a, b is separated into another high pressure stage 20. The single flow high pressure turbine 21 is provided with a bypass channel 24 comprising a pipe switch 70. The exhaust piece of the high pressure turbine 21 is commonly connected to the inlet of the low pressure turbine 31. Here, the bypass ratios of the two high pressure stages 20 can be set differently so that the distribution of the overall displacement can also be adjusted. As described, separation of the exhaust flow by the pipe switch 70 is possible in the high pressure turbine 21, the low pressure turbine 31, and the exhaust return 50.

Basically any turbine can be formed with a single flow, double flow or with a variety of turbine arrangements, in particular a distribution means having suitable vanes.

The diagram shown in FIG. 7 is similar to the diagram of FIG. 3. However, it includes a bypass line 86 that bypasses the high pressure compressor. The pipe switch 87 is also included. This embodiment has proved to be particularly useful for diesel engines, with a significant improvement in motor efficiency, fuel consumption and displacement at high speeds. In comparison, the technical effort is also relatively low.

The configuration of the present invention is useful for improving the motor efficiency and reducing fuel consumption and displacement of a diesel internal combustion engine.

Claims (10)

At least one high pressure stage 20 and at least one low pressure stage 30 disposed downstream of the high pressure stage 20, the inlet piece of the high-pressure turbine 21 and the exhaust piece of the engine 10 ( 12, the outlet piece of the high pressure turbine 21 and the low pressure turbine 31 are connected by pipes 60, 61; 62, 63 and 64, and have pipe switches 70 and 71 to exhaust the engine 10. In a turbocharged internal combustion engine further comprising a bypass pipe (24, 24a, 24b) for connecting the piece 12 to the inlet piece of the low-pressure turbine 31 and a sensor for sensing the operating parameters of the engine (10). , The high pressure turbine 21 always operates at the lowest displacement, which continuously circulates, A central processing unit (CPU) is provided to accept signals from the sensors, The CPU operates the pipe switches 70, 71, and 50 so that the changeable portion of the total displacement flows to the new air pieces of the high pressure turbine 21, the low pressure turbine 31, and the engine 10 to flow. Turbocharged internal combustion engine, characterized in that to optimize both the constant and non-constant operation mode of the engine (10) and to minimize the displacement. The high pressure turbine (21) is formed to have a double flow, and each flow (23a, b) is connected to the exhaust piece by another pipe (60, 61) separated from each other, the pipe ( Internal combustion engine, characterized in that it is provided with one bypass channel (24a, b) branching from (60,61). 3. A pipe switch (70, 71) is arranged in each of the bypass channels (24a, b), wherein the pipe switch comprises a low pressure turbine (31), a high pressure turbine (21), and an internal combustion. An internal combustion engine, characterized in that it is configured to distribute a partial flow to a new air piece (11) of the engine (10) and can be controlled singly (and / or) in common. 4. The method according to any one of claims 1 to 3, wherein the bypass channels (24, 24a, b) and outlet pipes lead to a common pipe (62), which is connected to a low pressure turbine (31). Internal combustion engine characterized by the above. 2. The high pressure and low pressure turbine (31) according to claim 1, wherein the high and low pressure turbines (31) are formed in double flow, and the bypass channels (24a, b) with pipe switches (70, 71) and one outlet pipe (63,64) Provided for each high pressure piece flow, each flow of the bypass channels 24a, b and outlet pipes 63, 64 is a flow 23a, 23b of the low pressure turbine 31 through the other pipe 62; An internal combustion engine, characterized in that connected to. The pipe switch (70, 71) is connected between the inlet pipe (60, 61) of the high-pressure turbine 21 and the bypass channels (24, 24a, b) according to any one of claims 1 to 5. An internal combustion engine, characterized in that it is arranged downstream of the point At least one high pressure step (20); At least one low pressure step (30) disposed after said high pressure step (20); A pipe for connecting the inlet piece of the high pressure turbine 21, the exhaust piece 12 of the engine 10, the outlet piece of the high pressure turbine 21, and the low pressure turbine 31; It is configured to include a sensor for detecting an operating variable of the engine 10, At least one of the two turbines has a distributing means having a variable turbine arrangement and particularly suitable vanes, The high pressure turbine 21 continuously flows by at least the lowest displacement, so it circulates continuously, A central processing unit (CPU) is provided to accept signals from the sensors, The CPU is a turbocharged internal combustion engine, characterized in that to change the arrangement of the turbine to have an optimized operating mode of the engine (10) to minimize fuel consumption and / or displacement. 8. The internal combustion engine according to claim 7, further comprising a bypass pipe bypassing the high pressure turbine (21), wherein the bypass pipe is provided with a pipe switch. 9. The internal combustion engine according to any one of claims 1 to 8, further comprising a bypass pipe bypassing the low pressure turbine (31), wherein the bypass pipe is provided with a pipe switch. 10. The method according to any one of claims 1 to 9, further comprising a bypass line (86) for bypassing the high pressure compressor, wherein the pipe line (86) is provided with a pipe switch (87). Internal combustion engine.